Waiotapu is an active geothermal area at the southern end of the Okataina Volcanic Centre, just north of the Reporoa caldera, in New Zealand's Taupo Volcanic Zone. It is 27 kilometres south of Rotorua. Due to dramatic geothermal conditions beneath the earth, the area has many hot springs noted for their colourful appearance, in addition to the Lady Knox Geyser, Champagne Pool, Artist's Palette, Primrose Terrace and boiling mud pools. These can mostly be viewed through access by foot, and in addition to a paid and curated experience, naturally forming hot springs appear around the area. The geothermal area covers 18 square kilometres. Prior to European occupation the area was the homeland of the Ngati Whaoa tribe who descended from those on the Arawa waka.

The area has a long history as a tourist attraction. While the area has been protected as a scenic reserve since 1931, a tourist operation occupies part of the reserve under a concession.

It operates under the name "Wai-O-Tapu Thermal Wonderland". The business was bought in 2012 by Te Arawa Group Holdings, a local Maori tribal business,
from the Sewell/Leinhardt family, who had run it for 30 years.

The Lady Knox Geyser is a geyser in the Waiotapu area of the Taupo Volcanic Zone in New Zealand. It is named after Lady Constance Knox, the second daughter of Uchter Knox, 15th Governor of New Zealand.

The geyser is induced to erupt daily at 10:15am by dropping a surfactant into the opening of the vent. Eruptions produce a jet of water reaching up to 20m and can last for over an hour,depending on the weather. The visible spout is made of rocks placed around the base of the spring to enhance the eruption;
over the years silica from the eruptions has built up to give a white cone-shaped appearance.

Well over a dozen craters are located in close proximity. They range from 5-50 metres in diameter and are up to 20 metres deep. All were formed by the ground surface collapsing.

The most recent collapse was Thunder Crater in 1968. Many craters have various types of geothemal activity including steam fumeroles,
sulphur vents and bubbling pools. Here water temperatures can range up to 80°C . Colors are introduced into the area by various oxides.